Marine fender

ABSTRACT

The invention relates to a fender for marine structures such as a support leg or column positioned to elevate a working platform above the water&#39;&#39;s surface. The fender is comprised of shockabsorbing members at least partially submerged to receive and absorb the impact of floating vessels, debris or the like. The fender includes cooperatively arranged hydraulic and pneumatic chambers, the hydraulic chamber being communicated with the body of water whereby to be maintained in a substantially full condition. The pneumatic chamber is separated from the hydraulic chamber by a yieldable diaphragm which is displaced into the air chamber as the fender is deformed in response to contact with a large floating body.

United States Patent l 13,s93,s31

[72] Inventors Fuad T. Saadeh;

lvo C. Pogonowski, both of Houston, Tex. I21] Appl. No 837,074 [22] Filed June 27,1969 1451 Patented July 20, 1971 [73] Assignee Texaco Inc.

New York, NY.

[54] MARINE FENDER 6 Claims, 5 Drawing Figs.

[52] U.S.Cl 61/48, 1 14/219 [5 1] Int. Cl E0211 3/22 [50] Field of Search l. 6 l [48, 46; 114/2 19, 220; 256/1 [56] References Cited UNITED STATES PATENTS 3,104,875 9/1963 Doyle 61/48 X 3,063,400 1 1/1962 Yamaguchi et a1. 1 14/219 3,276,414 10/1966 Lee 114/219 3,503,600 3/1970 Rich 61/48 X FOREIGN PATENTS 250,778 12/1963 Australia 114/219 Primary Examiner-J. Karl Bell Attorneys-K. E. Kavangh and Thomas H. Whaley ABSTRACT: The invention relates to a fender for marine structures such as a support leg or column positioned to elevate a working platform above the waters surface. The fender is comprised of shock-absorbing members at leastpartially submerged to receive and absorb the impact of floating I vessels, debris or the like. The fender includes cooperatively arranged hydraulic and pneumatic chambers, the hydraulic chamber being communicated with the body of water whereby to be maintained in a substantially full condition. The pneumatic chamber is separated from the hydraulic chamber by a yieldable diaphragm which is displaced into the air chamber as the fender is deformed in response to contact with a large floating body.

PATENTEU JULZO I97! Tlalh MARINE FENDER BACKGROUND OF THE INVENTION Most offshore platforms are located in such a position that ing vessels is relatively frequent and has been known to result in damage to the platform support legs particularly during inclement weather when the water tends to be turbulent. Under such conditions, violent slamming of the boat against the platform support columns not only results in damage to either the boat or the platform, but also in injury to personnel and loss of equipment.

Boat and marine fenders for protecting piers and other offshore structures are known to employ both pneumatic and hydraulic shock-absorbing elements. It is further known to enclose at least part of the fender element in resilient materials such as rubber or reinforced plastic whereby to define a relatively flexible wall casing.

In the instance of hydraulic-type chambers which most conveniently utilize sea water as the hydraulic medium, such a chamber is capable of withstanding and absorbing excessive forces applied thereto as by a floating vessel. However, in the normal hydraulic-type arrangement, once the hydraulic medium is forced from the chamber, the chamber reforms at a rela' tively slow rate. Thus, the fender is often incapable of sustaining and absorbing shocks applied at frequent intervals.

In the instance of a pneumatic-type chamber, such a unit is normally enclosed within a flexible body whereby a fixed amount of air or other gas may be retained within the body. For such units in general, the impact of a boat or similar mass against the pneumatic chamber causes the latter to deform and redistribute the air or gas as to absorb the shock and yet avoid rupturing of the external casing of the pneumatic unit.

OBJECTS OF THE INVENTION It is therefore one of the objects of the invention to provide a marine fender capable of absorbing relatively high impact 1 loads due to a vessel being brought into sharp contact with an offshore structure. A further object is to provide a shock-absorbing fender utilizing both hydraulic and pneumatic means as the absorbing elements. A still further object is to provide a marine fender of the type defined in which the absorbed energy is dissipated into the surrounding water by a plurality of high-velocity water jets.

The invention contemplated, in brief comprises a fender adapted for attachment to a marine structure positioned in a body of water. The fender includes a plurality of interconnected compartments, at least one being hydraulically inflated, one or more of the others being pneumatically inflated. Said compartments are so arranged as to be at least partially submerged in a body of water, extending for a distance above the waters surface. The fender is inwardly deformable whereby a floating vessel or other floating object upon forcibly contacting the fender outer surface will cause the wall to deform. The inward deformation in turn displaces a flexible diaphragm into a pneumatic compartment. Simultaneously, the externally applied force causes a forceful discharge of water from the hydraulic compartment through a plurality of constricted orifices. The latter compartment is communicated with a liquid source such as the water in which it is immersed whereby flow thereto is automatically achieved through a valved conduit as the compartment returns to its normal shape.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 illustrates an offshore platform of a type contemplated embodying a plurality of support legs each of which is provided with a fender as herein described;

FIG. 2 illustrates an enlarged segmentary view taken in cross section along line 2-2 in FIG. I;

FIG. 3 is a segmentary view on an enlarged scale similar to FIG. 2 showing however, the fender in a partially collapsed condition; v

FIG. 4 is a cross-sectional segmentary view on an enlarged scale of the present fender illustrating the use of internal biasing members positioned to assist the flexible walled fender in returning to its normal position; and

FIG. 5 is a view taken along line 5-'5 in FIG. 2.

FIG. 1 illustrates an offshore platform 10 of the type contemplated in which a working deck 11 is maintained above the water's surface- 12 by a plurality of rigid legs or columns 13 and I4 which supportably connect to the deck and extend downwardly through the water. Normally such legs are fixedly positioned at their lower ends by piling 16 or similar means to maintain the platform firmly at a desired location for drilling or producing purposes. Supporting legs 13 and 14 may be of an elongated cylindrical configuration or of the open-latticetype structure. v

Each upwardly extending leg such as 13, is provided with a fender 17 in the form ofa collarlike member which wraps,

about the leg at water level to be at least partially submerged and joined at connection I5: Collar or fender 17 maybe operably connected to or retained on an upright leg in such manner to permit longitudinal movement of the fender along the leg in response to variations in the level of the water as by tide changes and the like. However, for locations in which a minimal tide is realized, the fender assembly may be fixedly positioned on the leg in that the variation in the water level will be static. I i

It is appreciated that for relatively large legs where high seas occur, the fender may extend for a distance of 15 or 20 feet vertically. Whereas for shallow locations where little surface differential is expected the. size of the fender can be minimized, without detracting from its effectiveness.

In the present embodiment, fender assembly 17 is shown as being of a generally toroidal configuration when assembled to surround a portion of the upstanding platform leg 13 and be connected at the inner side of the leg. The fender includes a mounting plate 18 either slidably or fixedly positioned against the leg 13 outer surface and surrounding the latter.

The fender assembly is formed by a casing 19 connected to backup plate 18 and defining a hydraulic chamber about the latter. Said casing 19 as shown, includes an internalwall 2I disposed adjacent to and in abutment with backup plate 18, and opposite to an external wall 22. The respective walls 21 and 22 are connected at the lower side by a curved underpanel 23, and at the upper end by a flexible diaphragm 24. The connected walls thereby define a substantially closed hydraulic compartment 25 within the casing 19 confines.

Casing 19 is preferably formed of a flexible material such as reinforced rubber, plastic or Neoprene, to embody both strength and a-d'egree of resilience. The reinforcing component of the casing walls while not specifically shown, may comprise imbedded steel members or similar elements so oriented to provide the needed strength and desired flexibility. To permit assembly of the unit, diaphragm 24 is detachably connected to the casing 19 upper rim at inner and outer peripheral joints 26 and. 27 respectively whereby the diaphragm might be replaced in the event usage or abuse of the same causes wear or damage.

Casing I9 is in essence immersed within the body of water in its entirety and includes water-metering means in the form of a plurality of constricted openings or orifices 28 which are formed in the casing wallto discharge water into the external body of water. Thus, as the casing outer wall 22 is inwardly deformed, as shown in FIG. 3, liquid within hydraulic compartment 25 is compressed and forced through the respective orifices 28 thereby forming high-velocity jet streams 29. Compressing energy thus absorbed'by the deformation of hydraulic compartment 25 is expended by way of the jet streams 29 directed into the water body. The latter may be directed into Hydraulic compartment 25 is communicated with the sur-.

rounding sea water by a suction conduit 3] extending preferably from the casing under panel 23 and opening at av submerged port 32 into the ocean. Conduit 3 l is of a relatively large diameter to permit a rapid inflow of water at such time as casing 19 is returned to its normal, nondeformed position whereby incoming water will be in effect drawn into compart ment 25. A check valve 33 disposed in suction conduit 31 regulates the water inflow to permit unidirectional flow into compartment 25. On compression of the hydraulic chamber, check valve 33 closes thereby causing water to discharge through the respective constricted orifices 28.

A canopy or cover 34 carried at the casing 19 upper rim is fastened to the latter at the inner and outer peripheral joints 26 and 27. Said canopy is formed of a stiff, although flexible material, to define an internal pneumatic chamber 36 across diaphragm 24. Chamber 36 in normal position holds a quantity of air at ambient conditions and is so positioned with respect to diaphragm 24 that deformation of the latter in response to a pressure increase in compartment 25, will cause the diaphragm to expand and deform upwardly into said pneumatic chamber. I

Pneumatic chamber 36 may be provided with passage means 37 communicating the compartment with a source of air. For example, a valved conduit 39 extends from chamber 36 into the atmosphere, said conduit including a check valve 35 equipped with a bleed orifice. Thus, the chamber 36 is in constant communication with a source of air for filling the same as needed and stabilizing internal pressure.

As shown in FIG. 4, hydraulic chamber 25 is provided with internal biasing means such as discretely disposed compression springs 38 and 41 arranged between the opposed walls 21 and 22 of casing 19 as to normally function for returning the outer wall 22 to its expanded position. Said biasing meansis not intended primarily to absorb the initial shock of a vessel urged against the fender, which function is achieved by abovenoted constricted orifices. The springs however do urge outer wall 22 to a position whereby the check valve 33 may be open thereby permitting an inflow of water from the ocean to the hydraulic compartment 25.

In a further embodiment of the invention, and as previously noted, the entire fender assembly is adapted for longitudinal sliding movement on an elongated platform leg such as [3. In such instance, fender assembly 17 can be provided with a flotation feature such as a circular float connected to the fender lower side as to be submerged in the water whereby to urge the fender upwardly to a desired attitude and level with respect to the water level. The float may be of the variable buoyancy type such as one or more evacuable tanks. On the other hand it may'similarly comprise a porous buoyant material adapted to exert a continuous upward force on the fender assembly to achieve the above-noted positioning.

The novel fender herein described provides an effective, yet economical apparatus particularly adapted to use on an offshore platform where turbulent water and heavy ships are the norm. Under maximum loading conditions, a ship will completely deform at least part of the fender such that wall 21 is in virtual abutting engagement with wall 22.

The shock will then be absorbed by a combination of elements notably compression of springs 38 and 41'. deflection of diaphragm 24 into the pneumatic chamber 36, and the dissipation of water in the form of jets 29 from hydraulic chamber 25. In the instance of the annular unit shown, the shock will be distributed about the entire fender rather than concentrated at the point of impact. However, as a feature of versatility, the fender can be fabricated as discrete, and even separable units which are subsequently assembled to surround a platform leg.

Other modifications and variations of the invention as hereinbefore set forth may be made without departing from the spirit and scope thereof, and therefore, only'such limitations should be imposed as are indicated in the appended claims.

We claim:

1. The combination with a marine structure positioned at an offshore body of water and protruding upwardly beyond the surface thereof, of a fender for absorbing the force of floating objects coming in forceful contact with "said structure and comprising;

a deformable wall casing, being at least partially submerged in the water, said casing when in an undeformed condition including spaced-apart inner and outer walls defining an inner chamber therebetween, said inner wall having a rigid backup plate, and said outer wall being inwardly displaceable when contacted by a floating object,

a resilient diaphragm extending transversely of said casing and being attached to said spaced-apart inner and outer walls of the latter whereby to form separate liquid and pneumatic compartments within said chamber,

said liquid compartment beingat least partially submerged in the water and having a check valve means communicating said liquid chamber with said water whereby to maintain the quantity of water therein,

constricted passage means transversing said outer wall of said casing to communicate said liquid-holding compartment with the water whereby compression of said compartment due to a deforming force against the outer wall thereof, will exhaust water from said compartment through said restricted passage means and urge said resilient diaphragm into said pneumatic compartment.

2. In a marine structure as defined in clairn 1 wherein said constricted passage means includes a plurality of orifices formed along the outer wall of said casing normally contacted by said floating objects.

3. In a marine structure as defined in claim 1 wherein said casing is carried on said marine structure in such manner to curve said casing and provide a curved outer wall for contacting said floating object.

4. In a marine structure as defined in claim 1 including check valve means communicating said pneumatic chamber with a source of air to permit a unidirectional flow of the latter into said pneumatic chamber.

5. In a marine structure as defined in claim 1 including biasing means disposed in said hydraulic compartment and engaging the deformable outer wall thereof whereby inward deformation of the latter willcompress said biasing means.

6. In a marine structure as defined in claim 5 wherein said biasing means includes at least one compression spring being substantially horizontally positioned in said hydraulic compartment to urge said inner and outer walls apart in response to the inner deformation of said inner wall. 

1. The combination with a marine structure positioned at an offshore body of water and protruding upwardly beyond the surface thereof, of a fender for absorbing the force of floating objects coming in forceful contact with said structure and comprising; a deformable wall casing, being at least partially submerged in the water, said casing when in an undeformed condition including spaced-apart inner and outer walls defining an inner chamber therebetween, said inner wall having a rigid backup plate, and said outer wall being inwardly displaceable when contacted by a floating object, a resilient diaphragm extending transversely of said casing and being attached to said spaced-apart inner and outer walls of the latter whereby to form separate liquid and pneumatic compartments within said chamber, said liquid compartment being at least partially submerged in the water and having a check valve means communicating said liquid chamber with said water whereby to maintain the quantity of water therein, constricted passage means transversing said outer wall of said casing to communicate said liquid-holding compartment with the water whereby compression of said compartment due to a deforming force against the outer wall thereof, will exhaust water from said compartment through said restricted passage means and urge said resilient diaphragm into said pneumatic compartment.
 2. In a marine structure as defined in claim 1 wherein said constricted passage means includes a plurality of orifices formed along the outer wall of said casing normally contacted by said floating objects.
 3. In a marine structure as defined in claim 1 wherein said casing is carried on said marine structure in such manner to curve said casing and provide a curved outer wall for contacting said floating object.
 4. In a marine structure as defined in claim 1 including check valve means communicating said pneumatic chamber with a source of air to permit a unidirectional flow of the latter into said pneumatic chamber.
 5. In a marine structure as defined in claim 1 including biasing means disposed in said hydraulic compartment and engaging the deformable outer wall thereof whereby inward deformation of the latter will compress said biasing means.
 6. In a marine structure as defined in claim 5 wherein said biasing means includes at least one compression spring being substantially horizontally positioned in said hydraulic compartment to urge said Inner and outer walls apart in response to the inner deformation of said inner wall. 